Classifier



ATTOkA/EY s 6 N mm BN5. EH mm H A n Jan. 1), 1928.

Patented Jan. .10, 1928.

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ALBERT} H. S'I'EBBINS, OFYLOS AnGELns, CALIFORNIA.

, CLASSIFIER.

Application filed December 15, 1926. Serial No. 154,879.

This invention relates to classifiers ot' the type in which materials passing downwardly within a treatment chamber under the influence of gravity are subjected to the action of air currents that separate the liner. par ticles from the coarser materials.

In employing classifiers of this general type it is diihcult to effect a complete separation of the materials through the use 0'? an air blast alone, or through an air exhaust alone, and it the materials being treated are relatively line it will be necessary to subject them repeatedly to the action of separating air currents in order to remove completely the liner particles from the slightly larger particles. l The present invention is therefore directed to a multiple treatment classifier which is so constructed that as the materials pass downardly within the treatment chamber they are subjected time and time again to separating air currents whichgradually remove the liner particles from the slightly larger particles. 1

One important feature of the present invention resides in the novel constructionof the treatment chamber and in the arrangement of parts whereby air jets are provided within the treatment chamber at a number of points throughout its length, and also in the construction whereby air 'is exhausted from the treatment chamber at different points throughout its length. 7 4

Another feature of the invention resides in the arrangement of partitions within the treatment chamber to divide the same into anumber of settling compartments.

Another feature of the invention resides in means for introducing air from the atmosphere into the casing adjacent the lower ends of the partitions.

Still another feature of the invention resides in a novel type of closure for regulatiirg the flow of materials from the teed hopper to the treatment chamber.

Other features of the invention and novel combination of parts in addition to the above will be hereinafter described in connection with the accompanying drawings which illustrate one good practical. "form of'the invention.

In the drawings Fig. l is a vertical sectional view through a classifier constructed in accordance with the present invention; a

Fig. 2 is a top plan view of F1 1;

Fig. 3 is a sectional View taken on the line38 of Fig. 1; i i

Fig. l is a vertical sectional view of the lower portion of the classifier of Fig. 1, the shaded lines being omitted and the tion is taken so as not to cut the airinlet passages in the outer wall; and

Fig. 5 on an enlarged scale is a sectional view on the line 5 5 of Fig. 4.

In the embodiment of the invention illustrated the classifier is shown as cylindrical in'shape and as having a casinglO in which treatment of the materials is effected. About the casing10 is provided an outer cas. ing 11 that is supported in spacedrelation to the casing 10 to form the air exhaust passage l2 between-the two casings. The

upper. portion of the passage 12 flaresout- V wardly somewhat as at 13 to form an annular space 14 of increased area. Air is exhausted from the annular space 14.- by a suction pipe I5'that leads to the suction fan 16.

lVithin the casing 10 are provided a series of partitions 17 which serve to dividethe treatment chamber into a number of settling compartments. These partitions are shown as frusto-conical in shape and are sui'iporte'd one above the other in nested relation and the inclined walls of the partitions slope downwardly in a direction to direct the materials that settle upon the walls toward the central opening 18 at the lower end of each frusto conical partition. The upper ends of the partitions 17 preferably fit snugly within the casing 10 and may be riveted or otherwise secured to the wall 10.

The classifier of the present invention is supported in an upright position as shown so that the materials to betreated will pass downwardly within the treatment chamber under the influence of gravity. The total" length of the classifier and the number of partitions mounted within the treatment chamber will depend largely upon the nature of the materials being treated. If the materials being tr ated are relatively coarse then a few air treatments will serve to effect the desired separation, but it the classifier is designed to separate fine dust-like materials then a largenumber of treatments will be necessary to completely remove the finer particles from the slightly coarser particles, in whi'chcase alarge numberot par titions 17 should be provided.

In the embodiment of the. invention shown, the materials are delivered to the upper portion ot the classifier by a hopper l!) which may be mounted within the ow lindrical using it). The flow of materials ti-om the lower end ot the hopper into the treatment chamber is controlled by a closure or iuljustab head wiiieh is shown as mounted upon the centrally disposed a' )last pipe 21. The upper portion of the closure is conical in shape and is provided with the air apertures 22 through which air may escape into the hopper it) to prevent the mate rials from clogging at the discharge end of the hopper. Air under presure is delivered to the interior of the closure '20 by providing the air discharge openings 2 in the side walls of the air blast pipe ill. "the rate at which the materials are delivered to the treatment chamber by the hopper may be regulated by movi c the closure Q l length wip towards and from wise ot the air bl A the discharge end oil: the hopper, and the closure may be secured in the desired position of adjustment by tightening the clamping means 2ft" providedat the upper end of the closure to embrace the pipe The frusto-conical parti ions l? are supported in spaced relation to each other to form the settling 001111 artments or chambers 25 between them, as best shown in Fig. l.

Air under pressure is supplied to the air blast pipe 21 by the horizontally extending pipe 26 which leads from the blast fan 27, and the amount of air supplied to the blast pipe 21 may be controlled by adjusting the sliding gate 28. T he pipe is mounted centrally within the casing 10 and extends downwardly through the openii 18 ot the various partitions 17, and this pipe is provided at various points along its length with the air discharge openings 2?). These 01 ings are so positioned that as the materals passing downwardly within the clas itier escape from the discharge end 18 oi: one tru'sto-conical partition they will be carried outwardly and upwardly by the air blast into the next settling compartment 25. In this manner the materials are treated time and time again as they pass down vardly within the treatment chamber. jets employed to carry the materials into the settling compartments 25 should, be directed upwardly to some extent and to this end an annular tlange or the like 30 may be provided immediately below each group of openings 29 to direct the air currents upwardly slightly, as indicated by the arrows. The diameter of the air blast pipe 21 may be gradually decreased towards the lower end of the casing as willbe apparent from the drawing, and the lower end of this pipe may be provided with a discharge spout 31 through which the pipe may be blown out from time to time, but which spout is normally closed by the gate or valve 32.

The ht r n atenals l1 remain s s- The air air from the atmosphere isadmittm pended within the air in the settling con1- partments are preferably exhausted from the upper end of these (01111)111tl1101lt8, and this is accomplished. in the embodiment of the invention shown by proviong the passages 323 which lead from the upper portion 01'? the settling compartments to the air exhaustchamber 12, the arrangement being such that the air is drawn upwardly within the compartments 25 through the openings into the suction chamber 12 by the exhaust fan 16. The amount of air exhausted from the. suction chamber 12 by the tan ll) may be controlled by adjusting the sliding gate 34.

it will be undersloml that the heavier particles that settle within t he compartments 25 slide downwardly along the inclined walls of such con'i 'iurtments into the path of the next set ot air jets 29, to be carried upwardly into another settling compartment "for further treatment. The heavier mate rials that pass through the entire series of trusto-conical partitions will collect in the hopper 35 at the lower end of the classifier and from which they may be withdrawn from time to time by opening the discharge It will be apparent from the foregoing that the volume of air exhausted from the treatment chamber may be controlled by adjusting the gate 3i, and that the amount of air delivered to the treatment chamber by the air blast pipe ll may be controlled by adjusting the gate 28. lit the volume ot air removed from the treatment chamber should exceed the amoum of air delirered thereto, there would be a tendency to create a vacuum within the treatment chamber which would etl'ect the separatingoperation in order to prevent the formation ct such partial vacuum within the classifier it may be desirable to introduce air from the ati'nosphere into the treatment chamber. This is accomplished. in accordance'with the present invention b 7 arrano'in certain of the.

l m t:

conical partitions 17 so that the air inlet passages 37 are formed between them and .l to these passages by providing the air inlet ports 2-38 formed through the inner and outer casings l0 and 11. The amount of air admitted to the treutn'ient chamber through the poll? 38 may be controlled by adjusting the gates 39 mounted upon the outer casing ll to cover the outer ends of the ports 38. The arrangement just described is such that the air introduced from the atmosphere will move downwardly within the space 37 between adjacent partitions and will flow upwardly around the lower end of a partition into a settling compartment This arrangement has the advantage that he air from the atmosphere passing upwardly around. the lower end. of haste-conical ill) llll) lll fier may be accuratelycontrolled, and sincethe materials passing downwardly within the classifier are subjected time and time again to the separating action of the rising air currents, a thorough separation of the materials may be secured. The particleswhich settle within'the air exhaust passage 12 will move downwardly into the discharge hopper 40 from which they maybe drawn from time to time by opening the discharge gate 41.

hat is claimed is:

1. A'classifier comprising in combination,-

an upright casing, means for delivering the materials to be treated to the upper portion of the casing to pass downwardly within the central portion of the casing, frustoconical partitions supported one. above the other about the central aXis of the casing to form downwardly inclined settling chambers between them and the partitions being constructed to direct the particles sliding down their inclined walls toward said central aXis, means forproducing air jets Withinthe casing for'blowing the fallingmaterials outwardly into the settling chambers, and means for removing from the settling chambers the lighter in the air. v

2. A classifier comprising in combination, an upright casing, an air blast pipe mounted centrally within the casing and having air discharge openings provided at intervals along the pipe, means for delivering the materials to be treated into the upper portion of the casing to pass downwardly therein, frusto-conical partitions surrounding 'said pipe and arranged in spaced relation to each other to form settling chambers between them and constructed so that the materials that settle upon the inclined walls of the partitions will slide down these walls toward said pipe and into the path of theair blast,

and means for removing from the settling chambers the lighter suspended in the air. V

3. A classifier comprising in combination, an upright casing constructed to form a treatment chamber, means for delivering the particles that remain materials to be treated to the upper portion of the casing to pass downwardly within the central. portion of the casing, frusto-conical partitions supported one above the other within the casing in spaced relation to form Settling chambers between them and corn particles that remain suspended structed to direct the particles that settle upon the inclined walls of the partitions 7 toward the central axis ofthe treatment chamber, means for removing from thesettling chambers the lighter particles that r main suspended in the air, and means forming air inlet passages for conducting air from the atmosphere into the casing around the lower edge of the conical partitions.

a. Aclassifier comprising in combination, an upright casing constructed to form a treatment chamber, means for delivering the materials to be treated to'the upper portion otthe casing to pass downwardly within the central portion of the casing, frusto conical partitions supported one above the other within the casing in spaced relation to form settling chambersbetween them and. mnstructed to direct the particles that settle upon the inclined walls of the partitions toward the central axis of the treatment chamber, means for removing from the settling chambers the lighter particles that remain suspended in the air, means forming air inlet passages'for conducting air from the atmosphere into the casing around the .lower edge of the conical partitions, and

adjustable means for regulating the amount of air admittted to the casing from the atmosphere.

5. A classifier comprising in combination, an upright casing, means for delivering the materials to be'treated to the upper portion oi the casing to pass downwardly therein, frusto-conical partitions supported one above the other in the casing :to town settling chambers between" them and provided with central openings through which the mate, rials are directed by the inclined walls of the partitions, a blast pipe mounted centrally within the casing and providedwith apertures at intervals along its length for directing air currents against the falling materials to carry the materials upwardly into the settling chambers, and means for exhausting air from the upper portion of the settling chambers.

6. A classifier comprising in combination. an upright casing, an air blast pipe mounted centrally within the casing, means for delivering the materials tobe treated to the upper-portion of the casing to pass down wardly therein adjacent said pipe, partitions mounted in the casing in spaced relation to each other to form settlin chambers between lill) Jun upper portion of the casing to pass downwardly therein adjacent said pipe, partitions I mounted in the casing in spaced relation to each other to form settling chambers between them and having inclined walls tor directing the materials that settle in the chambers toward said pipe, means for exhausting air from the settling chambers, and the air blast pipe being provided with air blast openings through which air is directed against the tailing material to carry them into the settling rhainbers. V V

8. A classifier comprising in combination, an upright cas ng" having formed therein a. treati'i'ient chamber, means for delivering the n'ia-terials to be treated to the upper part oi said casing to pass downwardly therein, partitions mounted in the casing in spaced relation to each other to form settling chain-- here between them and having inclined walls for directing the materials that settle in the chambers toward the central axis of the casing, means t directing jets of air against the materials moving downwardly within the i casing to carry them into the settling chambers, and means surroundine said casing for exhausting air from the settling chambers.

9. A classifier comprising in combination,

an upright casing having a treatment chamher, an outer wall surrounding said casing and forming an air exhaust chamber surrounding said casiny, inclined partitions mounted in the casing in spaced relat on to each other to "form settling chambers be tween them, means for deliver-i the materials to be treated into the upper portion of said casing to move downwardly therein, means forming a communication between said exhaust chamber and the settling chambers and means for exhausting air from the exhaust chamber to carry oil the lighter materials within the casing.

. 10. A classifier comprising; in combination, an upright casing having a treatment chainber, an outer wall surrounding said casing and forming an air exhaust chamber surrounding said casing, inclined partitions mounted in the casing in spaced relation to each other to form settling chambers between them, means for delivering the materials to be treated into the upper portion of the casing to pass downwardly therein, means l'orn'iing an air passage between said exhaust chambc and the settling" chambers to cited the removal of the lighter particles that remain suspended in the air from the settling chambers, and air inlet ports formed through said outer wall for admitting air from the atmosphere into the int 'ior of said casing. 11. A classifier compri ing in combination, an uright casing, a series of ii'rusto-conical partitions mounted in the casing in nested relation and arranged to form settlingchainbers between some of the partitions and air inlet chambers between other partitions and through which air is conducted downwardly to the lower ends of the partitions, means for delivering the materials to be treated into the upper portion of the casing to more downwardly therein through central openings in the partitions, means for introducing air from the atmos 'ihere into the casing betw'en certain partitions, and n'ieans for e hausting air from saic settling chambers.

A. classifier comprisii'ip; in con'ibination, an upright casing, an air blast pipe mounted 'ithin the casing, inclined partitions mount ed in the casing in spaced relation to. each other to form settling chambers between them and provided 'ith downwardly sloping walls that dire;tthe materials toward said pipe, teed hopper surrounding said pipe, and an annular closure for the lower end of the feed hopper adjustably mounted upon said pipe and movable lengthwise of the pipe to vary the size of the feed opening.

13. A classifier comprisisinp; in combination, an upright casing, an air blast pipe mounted within the casing, inclined partitions monnted in the casing in spaced relation to each other to form settling chambers between themand provided with downwardly sloping); walls that direct the materials toward. said pipe, a feed hopper for delivering mate to the casing, a closure for the lower 0 the feed hopper and constructed to surround said pipe and provided with air discharge apertures, and means for introducing air, into the closure from said pi ie to produce air jets through said apertures to promote feeding of the materials.

14. A classifier comprising in combination, an upright casing, means r del vering the materials to be treated to the upper portion of the casing to pass downwardly therein under the influence oi ravity, a series of frusto-conical partitions mounted one abo e the other in nested relation to form downwardly inclined settling chambers between them and which are shaped to direct the materials moving downwardly within the chainbers toward the central axis of the casing, an annular wall {H.Tlllllttl at the upper of each partition and arrai'iged to provide a narrow annular slot at the upper end f each settling chamber, means tor exhausting: air from the settling chambers through said narrow slots, and means for blowing the mate rials moving downwardly within the casing outwardly into the settling chambers.

In testimony whereof, I have signed my name to this specification.

ALBERT n. srnnnnis.

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